Linux down to open port

First, I'd like to recommend a blog post here.

http://blog.csdn.net/zht666/article/details/17505789

This article is written in very detailed, contains the operation of the port some commands, we operate the port is actually operation iptables this file.

1. View Port

Iptables-l-N

2. Add Port

Iptables-a input-p TCP--dport 22-j ACCEPT

Note: INPUT is a group of its own, according to the actual system configuration to fill in.

Here we recommend an article:

Http://www.zybang.com/question/b0b8264a278253054b96aa87426dba1b.html

The same Add statement I choose the following sentence:

Iptables-a input-p tcp-m State--state new-m TCP--dport 22-j ACCEPT

In my actual system I changed to this:

Iptables-a in_public_allow-p tcp-m State--state new-m TCP--dport 22-j ACCEPT

3. Delete Port

To delete a port first check the NUM number by using the following statement:

Iptables-l-N--line-number

Num Target prot opt source destination
1 DROP TCP--0.0.0.0/0 0.0.0.0/0 TCP dpt:3306
2 DROP TCP--0.0.0.0/0 0.0.0.0/0 TCP dpt:21
3 DROP TCP--0.0.0.0/0 0.0.0.0/0 TCP dpt:80

See the first column of NUM, use this number to delete;

iptables-d INPUT 1

Executing the above statement removes the NUM number 3306 port number.

Linux down to open port